Attention deficit hyperactivity disorder (ADHD) is a behavioural disorder that includes symptoms such as inattentiveness, hyperactivity and impulsiveness.

Symptoms of ADHD tend to be noticed at an early age and may become more noticeable when a child's circumstances change, such as when they start school. Most cases are diagnosed when children are 6 to 12 years old.

The symptoms of ADHD usually improve with age, but many adults who were diagnosed with the condition at a young age continue to experience problems.

People with ADHD may also have additional problems, such as sleep and anxiety disorders.

Getting help

Many children go through phases where they're restless or inattentive. This is often completely normal and does not necessarily mean they have ADHD.

However, you should consider raising your concerns with your child's teacher, their school's special educational needs co-ordinator (SENCO) or GP if you think their behaviour may be different from most children their age.

It's also a good idea to speak to your GP if you're an adult and you think you may have ADHD but weren't diagnosed with the condition as a child.

What causes ADHD?

The exact cause of ADHD is unknown, but the condition has been shown to run in families. Research has also identified a number of possible differences in the brains of people with ADHD when compared with those without the condition.

Other factors suggested as potentially having a role in ADHD include:

being born prematurely (before the 37th week of pregnancy)

having a low birthweight

smoking, or alcohol or drug abuse during pregnancy

ADHD can occur in people of any intellectual ability, although it's more common in people with learning difficulties.